Max power draw on wall plug

[mibloem]

How much power can I safely draw from a single wall plug?

 

[Okty]

That’s if the voltage is 220.

Mine is sometimes almost 240.

 

[Geoff.D]

That’s if the voltage is 220.

Mine is sometimes almost 240.

Just recalculate as above using 240 V. The max current you can draw is determined by the rating of the CBs, which is 20A.

 

[chrisc]

This assumes that nothing attached to the same circuit-breaker is also drawing power and that the socket, plug and wiring is in proper order and clean

I’d suggest you don’t exceed 75% of the rated capacity

 

[Okty]

Just recalculate as above using 240 V. The max current you can draw is determined by the rating of the CBs, which is 20A.

But technically, if a wall socket is rated max for 15amps @ 220v (3300 watt), will it be unsafe to draw 15 amps @ 240v (3600 watt)?

I assume the socket equipment actually have a safety factor in it to actual function with higher loads than what is stated.

Edit, when did it change to 15 amps? Bought new wall plug replacements the other day, still states 16 amps max on it.

 

[PaulGherkin]

Older (SABS Approved) plug sockets made in the 80s... 18-20A easy without a sweat
The new junk on the market, made in China on behalf of Clipsal and the Chinese clones.... not more than 10A or you will end up with a fire. That junk melts like cheese.

Breaker rating is 20A for plug sockets. This is standard as per SANS code of practice.

 

[Geoff.D]

But technically, if a wall socket is rated max for 15amps @ 220v (3300 watt), will it be unsafe to draw 15 amps @ 240v (3600 watt)?

I assume the socket equipment actually have a safety factor in it to actual function with higher loads than what is stated.

Edit, when did it change to 15 amps? Bought new wall plug replacements the other day, still states 16 amps max on it.

Yes, it is 16A. And that is determined by the maximum rating of CBs, which are specified to be16A + 25% overload = 20A.
So, IF you plug in something that draws mow than the rated amount plus 25% is WILL trip the CB.
This assumes of course, that there are no other appliances drawing current on the circuit at that time. If there are, the trip WILL occur as soon as the accumulated draw exceeds 20A.

 

[Tman543]

16A according to SANS, this is actually determine by two things the wiring (2.5mm amp rating) and the CB rating. In the end, the max current on the plug will be limited by these two items.

 

[Tom427]

Don't know about SANS, but 1,5mm2 cable was rated 16A in Germany, when I was there in 1984.
If you draw more power, the 16A breaker will trip.

Now there are fast and slow breakers. If your power tool draws above 16A on start-up, and drops below during longer use, you can be fine.

On a side note: The 5-way adapters (from China?) with their internal fuse, switch off too early. I feel they are rated closer to 10A. Would be nice to check some time.

 

[Pineapple Smurf]

Just remember this is for the entire socket range.
Not 16 amps each
As the entire socket will be sharing 1 common set of wires going back to the ditribution wall

You cannot go 3000 watts on both sockets at the same time

 

[ToxicBunny]

Just remember this is for the entire socket range.
Not 16 amps each
As the entire socket will be sharing 1 common set of wires going back to the ditribution wall

You cannot go 3000 watts on both sockets at the same time

View attachment 1207948

Well beyond that, given how most houses are wired, its 3000watts across multiple plug points as well. You can just hope the DB board is labelled correctly, and that plug point isn't magically on a light circuit

 

[thehuman]

I would say 1 socket is rated at 16 amps

But cable and circuit breaker rated for 20a
So i would say a double socket can handle upto 20a but limited to 16a per plug.

 

[Pineapple Smurf]

Well beyond that, given how most houses are wired, its 3000watts across multiple plug points as well. You can just hope the DB board is labelled correctly, and that plug point isn't magically on a light circuit

I just checked my flat and I have 7 wall plugs in total going to 3 x 20amp breakers
So if I ran 3500 Watts x 2 on each wall plug (they're double plugs as per previous pic) that equals 49000 Watts / 240volts = 204 amps



Either my maths sux right now after a few beers or I must never load my plugs with that many heaters

 

[krieg]

I just checked my flat and I have 7 wall plugs in total going to 3 x 20amp breakers
So if I ran 3500 Watts x 2 on each wall plug (they're double plugs as per previous pic) that equals 49000 Watts / 240volts = 204 amps



Either my maths sux right now after a few beers or I must never load my plugs with that many heaters

Your cb's will trip almost immediately with that load. You only have 60 amps incoming to your flat so only 4 heaters at a time.

 

[Geoff.D]

I just checked my flat and I have 7 wall plugs in total going to 3 x 20amp breakers
So if I ran 3500 Watts x 2 on each wall plug (they're double plugs as per previous pic) that equals 49000 Watts / 240volts = 204 amps



Either my maths sux right now after a few beers or I must never load my plugs with that many heaters

I have just had a CoC done. My home has 2.5 mm sq wiring and 30 A breakers with no more than 4 sockets per breaker.

This new crap using 1.5 mm sq wiring and 20A breakers is just a BS shortcut!
The electrician buggered around and scratched and finally found ONE socket that he says I have to change because it is tripping the EL at 30mA instead of 20 mA.
He wet himself because he found a circuit I use for the fridges and freezers NOT on EL. In fact, if my wife had kept her mouth shut he would not have found that circuit.

That is all he found. You should have seen the long face because both so-called problems were solved by me while he waited. A loose earth connection and I simply disconnected the other circuit. The new owner can do whatever he likes.
Not bad for a house that has not seen the likes of an electrician in 40 years.

 

[RonSwanson]

I have just had a CoC done. My home has 2.5 mm sq wiring and 30 A breakers with no more than 4 sockets per breaker.

This new crap using 1.5 mm sq wiring and 20A breakers is just a BS shortcut!
The electrician buggered around and scratched and finally found ONE socket that he says I have to change because it is tripping the EL at 30mA instead of 20 mA.
He wet himself because he found a circuit I use for the fridges and freezers NOT on EL. In fact, if my wife had kept her mouth shut he would not have found that circuit.

That is all he found. You should have seen the long face because both so-called problems were solved by me while he waited. A loose earth connection and I simply disconnected the other circuit. The new owner can do whatever he likes.
Not bad for a house that has not seen the likes of an electrician in 40 years.

Are you selling? Where to?

 

[krieg]

I have just had a CoC done. My home has 2.5 mm sq wiring and 30 A breakers with no more than 4 sockets per breaker.

This new crap using 1.5 mm sq wiring and 20A breakers is just a BS shortcut!
The electrician buggered around and scratched and finally found ONE socket that he says I have to change because it is tripping the EL at 30mA instead of 20 mA.
He wet himself because he found a circuit I use for the fridges and freezers NOT on EL. In fact, if my wife had kept her mouth shut he would not have found that circuit.

That is all he found. You should have seen the long face because both so-called problems were solved by me while he waited. A loose earth connection and I simply disconnected the other circuit. The new owner can do whatever he likes.
Not bad for a house that has not seen the likes of an electrician in 40 years.

Those 30a breakers are essentially useless as the max current on a 2.5 mm² cable is 25 amps which is why 20a breakers are usually used. 1.5mm² cable is usually a 10a breaker or lower.

 

[RudderVator]

Plugs supplying fridges , alarms systems , IT equipment doesn't not have to be on an EL.

All plugs in residential install must be earthed on the earth leakage.

Fridges are actually very critical to be on Earth leakage because what if the body becomes live due to a bad defrost heater or something else?

 

[Pineapple Smurf]

All plugs in residential install must be earthed on the earth leakage.

Fridges are actually very critical to be on Earth leakage because what if the body becomes live due to a bad defrost heater or something else?

Agree 100%

2 prong devices like drills and jigsaws and blenders and clock radios etc all have plastic bodies and therefore cannot shock you. (unless you're a total idiot)
Anything with metal must be earthed like your microwave oven, toaster, kettle etc

 

[Geoff.D]

SANS10142-1
View attachment 1208234


Although best practice to have all your socket outlets connected to an EL, in terms of issuing a compliance certificate as in Geoff case you need to be careful when you use words like shall and must .

Exactly! The circuit was/is dedicated to fridges and freezers with specialised plugs and coloured covers.

Hence it complies. as per above.

In any case, I will show the new owner what to do if he chooses to remove them from E/L.